One thought that has been expressed in some earlier posts is to have smoothed out the so-called ravine. It most likely can’t be made flat, as some have suggested, because the topography of the whole area slopes downwards to the right (east). The right hand runway, 36R, is about 25m lower in elevation than the left hand runway used by the aircraft, 36L, at a point abeam the aircraft’s final resting place.
I’ve looked at getting a cost for smoothing out the so-called ravine a few times, and it is hard to estimate accurately as I am using only Google Earth for topographical data. Plus costs on airports in capital cities have a habit of being anything up to three times higher than in rural airports due to the multiplicity of services, authorities, work constraints, etc. However what I’ve got so far is the following.
To make things smooth, we need to fill in the ravine. This ravine carries a river which is obviously part of the airport and area drainage system, so it needs a main stormwater drain to be installed to carry the river water, and then the ground to be filled in above the drain. We need 2.5 km of main piped stormwater drain for the river between the two runways and extending around the end of 18R, and another 1 km of pipe drain for the smaller river that flows between the runways about halfway along the runway. My cost estimate for those two stormwater pipe drains is US $20 million. We also need a large amount of fill to cover the drainage pipes and to smooth out the terrain. A really approximate guess, using Google Earth data, is that 2 million cubic metres would be needed. That could cost anywhere between $20-70 million depending on haulage distance and cost of quarry/fill material in Madrid. Then add in design, contract administration, and contingencies, and the sort of cost to smooth the terrain is about US $100 million. That could of course be more because of the urban factor.
That is a lot of money. My concern, and this has been expressed by other posts, is where do you stop making the area around an airport smooth? Here, and assuming we do make the ground smooth between the two runways, albeit at an overall slope of 2% downwards, let us look to the left of the runway. The ground rises at a gradient of 9% for some 500m. There is also a small ravine on the left about halfway along the runway. If the aircraft had gone off to the left, and assuming it missed the ravine, I would have thought the aircraft with a tricycle undercarriage configuration travelling at say 160 knots diagonally up a 9% slope over grass would still be rather likely to break something or wobble and clip the ground with a wing. The chance of a crash and fire is significant, and the success of a diversion to the left is not assured. So do we remove that hill? And what about the end of the runway, and running over the end. Maybe we need to extend the RESA of this already very long runway. And don’t forget the distant high ground to the north of the runway; maybe we need to level some of those distant mountains. Where does the work stop?
The answer IMHO is the balance between risk and cost. Despite this tragic accident, if I look at the collective risk for airline passengers in Spain and relate it to individual risk, it is still below the accepted individual risk level. The Dutch government assessed the individual risk level of 1 x 10E-6 as that which would trigger effort to reduce risk (from the Schipol accident, 1992). Even after this accident, Spain is below this, and as such effort is probably not justified to further reduce the risk.
Bringing the argument back to ICAO rules, I suggest that despite this accident, the cost to reduce the risk by smoothing the terrain beyond ICAO requirements is not justified by the reduction in risk.
There remains the test of negligence. For risk analysis, this is prefaced by dictum of the former Chief Justice of the High Court of Australia, Hon. Justice Gibbs, who in determining negligence on the handling of risk stated:
“Where it is possible to guard against a foreseeable risk which, though not perhaps great, nevertheless cannot be called remote or fanciful, by adopting a means which involves little difficulty or expense, the failure to adopt such means will in general be negligent.”
IMHO by meeting ICAO standards, as it seem evident that Madrid does, it means the risk of this tragedy is remote. Furthermore my cost estimate shows that to guard against it involve great expense and some difficulty. So no negligence could be attached in the handling of risk.
IMHO, the buck stops if an airport meets the ICAO rules. I reckon ICAO rules are a very good balance between risk and cost, and they have stood the test of decades of time.